yeah. that would be a problem. However, I would hope Blizzard would be smart enough to not have the “forfeit” button option available until well into the game, and then also require specific stats before the ‘forfeit’ button is triggered by the game to become available. Example, no progress for capture/push, team kill difference of 3 to 1 (or higher?), etc.
The match would have to meet a certain criteria before the “mercy” rule could/would trigger the ‘forfeit’ option.